Integer Audio

GroundControl Energy Decay Meter v11.5

← GroundControl
Before you start — four things to check:
1. Turn on your studio monitors or subwoofer and connect them as the default audio output.
2. Place a measurement mic (e.g. UMIK-1) at your mix position at ear level.
3. Keep the room quiet during the sweep — no fans, no HVAC if possible.
4. For a valid before/after, do not move the mic or change the playback volume between the Baseline and Nodal 30 sweeps. The bass field changes over a few centimetres, so any movement or level change invalidates the comparison.
Your browser will request microphone permission when you click Connect & Calibrate.
Sweeps to average: — more sweeps = better noise rejection
STEP 01
Connect mic & calibrate
STEP 02
Run baseline sweep — untreated
STEP 03
Verify Nodal 30 treatment
Calibrating… Please wait.
v11.5 — Decay accuracy fix
• Fixed decay times reading ~2× too long — the analysis filter was too narrow and its own ring was being counted as room decay (now a half-octave filter by default, with a bandwidth selector to match your REW band setting)
• Much lower measurement floor, so high frequencies and tight rooms now show real values instead of dropping out
• Bars now at 2 Hz with an auto-scaling time axis; plain-language tight / boomy / rings-on definitions
• Exact T60 chart still under "exact decay times"
How to read your results

Each bar is a 2 Hz slice of the bass. Its length is how long that note keeps humming after the sound stops — shorter is better.

Tight — under ~0.35s. Clean, controlled bass.

Boomy — ~0.35–0.55s. Noticeably thick or heavy.

Rings on — over ~0.55s. The note drones on after it should have stopped, smearing other notes and making bass sound muddy or "one-note."

The faint bar is your room before treatment; the solid bar is after. Greyed "near limit" notes are too low/quiet to prove further improvement.

Measurement in Progress
Initialising…
Keep the room quiet.
Your Room's Bass Decay — 20–80 Hz Baseline Captured
Run the baseline measurement to see how long your room holds onto bass.
Analysis bandwidth: ⓘ why?
before → after
tight boomy rings on before measurement limit Tap any note for detail
Show exact decay times (T60 per frequency)
Frequency
Baseline
Nodal 30
Δ
Before After Filter floor Low confidence Contamination
Adaptive Schroeder T30/T20/T10 · half-octave analysis filter · 1 Hz steps. The purple dashed line is the analysis filter's own ring-down floor — points at/below it (hollow rings) are limited by the measurement, not the room. Hover any frequency for its fit confidence and floor value.
Loopback Test
Zoom:
Connect & Calibrate first, then click Run Loopback Test.
Integer Audio // GroundControl
Room Acoustic Decay Report
Nodal 30 Bass Treatment — Before & After Verification
Generated
Test Status
MethodSchroeder T60 · ½-oct · 1 Hz steps
Room Dimensions
About This Test

This report measures how long bass energy lingers in the room after a tone stops, across the 20–80 Hz range. A Schroeder backward integration method is used with a half-octave analysis filter at 1 Hz steps across the band.

Method: Schroeder backward integration, adaptive T30/T20/T10 fit (whichever the usable dynamic range supports), extrapolated to 60 dB, using a half-octave bandpass by default. The average reduction uses only bands measured reliably in both the before and after sweeps. The dashed line on the chart is the analysis filter's own ring-down floor (≈0.32 s at 20 Hz falling to ≈0.08 s at 80 Hz at the half-octave default; the bandwidth selector changes it); values at or below it are limited by the measurement, not the room, and are excluded. Narrow peaks >1.0 s are flagged as potential contamination.

Detailed Decay Times (technical)
Notes
(Room configuration, Nodal 30 placement, date of installation…)